This invention relates to an electroluminescent panel for use in terminal equipment and other display devices of an electronic computer system so as to display a static image, a moving picture, and the like.
As will later be described in detail, a conventional electroluminescent panel comprises a transparent insulator substrate, such as glass, a plurality of parallel transparent electrodes, a plurality of back electrodes extended at an agle with respect to the transparent electrodes, and an electroluminescent laminate block between the transparent and the back electrodes. Such an electroluminescent laminate block usually comprises an electroluminescent layer and at least one dielectric layer.
With this structure, the electroluminescent laminate block is subject to the influence of moisture when exposed to an atmosphere. Such moisture gives rise to dielectric breakdown of the dielectric layer when moisture invades the electroluminescent layer during exposure of the electroluminescent panel to the atmosphere. Such invasion of the moisture into the electroluminesent layer makes the life of the electroluminescent panel undesirably short.
In order to protect an electroluminescent panel from invasion of moisture, an electroluminescent panel has been proposed in Japanese Patent Publication No. Syo 58-55,634, namely, 55,634/1983. The proposed electroluminescent panel comprises a cover plate of glass which completely envelops the electroluminescent laminate block with an air gap left between the cover plate and the electroluminescent laminate block. A silicone oil fills the air gap to absorb moisture. As a result, the electroluminescent laminate block is hermetically sealed by the cover glass.
However, it is to be noted that water can not be completely removed from the silicone oil but inevitably remains as remnant water in the silicone oil. Accordingly, the remnant water invades the electroluminescent laminate block and brings about degradation of a characteristic of the electroluminescent panel.
In addition, the use of the cover plate and the silicone oil makes the electroluminescent panel intricate in structure and its manufacture complex.